This is a general support, service-providing project covering two major activities. One activity includes service-providing studies of visual function for the supportive or collaborative diagnosis, evaluation, and follow-up of patients with inflammatory, degenerative, toxic, or congenital disorders. These activities include all of the routine electrophysiological and phychophysical testing of inpatients, outpatients, and referred consult cases seen in the NEI's Eye Clinic. In this fiscal year about 2300 tests will be performed with a total of ca. 14,000 tests performed over the last six years. In addition, these activities also provide most of the current "specialized" testing on visual sensory neural function of patients, often under collaborative arrangements with other sections of the Clinical Branch. The other activity involves the development of new tests for clinical studies using non-invasive electrophysiological and psychophysical measurements. Such tests, developed under this project, are, upon successful completion, assigned to separate projects for normative and clinically applied studies. Efforts continue toward the development of tests centered around a system of retinal-image stabilization which is currently being used for studies of selected cases.